A recipe for regeneration Unlike humans, planarian flatworms can regenerate certain tissues. During regeneration, existing tissues remodel, and undifferentiated and progenitor cells convert into specialized cell types at specified locations. Atabay et al. examined planarian eye regeneration (see the Perspective by Tanaka). Surgical and transplantation experiments revealed three properties governing regenerative progenitor behavior: cell self-organization, an extrinsic migratory target for progenitors, and a broad progenitor-specification zone. Predictions from this model enabled generation of animals with multiple stable eyes. Science, this issue p. 404; see also p. 374 Surgical manipulation and tissue transplantation elucidate the logic of pattern formation during eye regeneration in flatworms. During animal regeneration, cells must organize into discrete and functional systems. We show that self-organization, along with patterning cues, govern progenitor behavior in planarian regeneration. Surgical paradigms allowed the manipulation of planarian eye regeneration in predictable locations and numbers, generating alternative stable neuroanatomical states for wild-type animals with multiple functional ectopic eyes. We used animals with multiple ectopic eyes and eye transplantation to demonstrate that broad progenitor specification, combined with self-organization, allows anatomy maintenance during regeneration. We propose a model for regenerative progenitors involving (i) migratory targeting cues, (ii) self-organization into existing or regenerating eyes, and (iii) a broad zone, associated with coarse progenitor specification, in which eyes can be targeted by progenitors. These three properties help explain how tissues can be organized during regeneration.

中文翻译：

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自组织和祖细胞靶向在涡虫再生中产生稳定的模式

再生配方与人类不同，涡虫扁虫可以再生某些组织。在再生过程中，现有组织重塑，未分化细胞和祖细胞在特定位置转化为特化细胞类型。阿塔拜等人。检查涡虫眼再生（见田中的观点）。手术和移植实验揭示了控制再生祖细胞行为的三个特性：细胞自组织、祖细胞的外在迁移目标和广泛的祖细胞规范区。该模型的预测能够生成具有多个稳定眼睛的动物。科学，本期第 3 页。404; 另见第 374 手术操作和组织移植阐明了扁虫眼再生过程中图案形成的逻辑。在动物再生过程中，细胞必须组织成离散的功能系统。我们表明，自组织以及模式线索控制着涡虫再生中的祖细胞行为。手术范式允许在可预测的位置和数量上操纵涡虫眼的再生，为具有多种功能性异位眼的野生型动物产生替代的稳定神经解剖状态。我们使用具有多个异位眼和眼移植的动物来证明广泛的祖细胞规格，结合自组织，允许在再生过程中进行解剖维护。我们提出了一个再生祖细胞模型，涉及（i）迁移靶向线索，（ii）自组织成现有或再生眼睛，以及（iii）与粗略的祖细胞规格相关的广阔区域，其中眼睛可以被祖细胞靶向。这三个特性有助于解释组织在再生过程中是如何组织的。